Tagamet is a brand name medication used for treating gastroesophageal reflux disease (GERD), ulcers, and other conditions caused by excess stomach acid. The active ingredient in Tagamet is cimetidine, and there are several synonyms for this medication. Some of the common synonyms include Acid-Eze, Cimet, Cimetidine, Dyspamet, and Peptol. Other brand names of cimetidine include Biomet, Cinulcer, Elmetidine, Gastromax, H-cid, and Ulceron. As with any medication, it's essential to follow the recommended dosage and consult with a healthcare provider before taking Tagamet or any of its synonyms.